Analysis of the Single Phase Earth Faults and the Asymmetry in Compensated Medium Voltage Power Electric Networks

The publication discusses the variation of the regime parameters for earth connections neutral in compensated medium voltage mains. Simulation models of a medium voltage power grid are made. The studies on the change of the regime parameters at ground connection were made with exact, undercompensation and overcompensation. The influence of compensation, transient resistance and emergency asymmetry over the change of the operating parameters for overhead power networks is analyzed. The multiplicity of transient overvoltage, the multiplicity and duration of the transient earth connection current and the maximum value of the surge in the neutral are calculated. Studies have been made on the stationary voltages in the neutral side of the medium voltage of the power transformer in case of emergency asymmetry by interruption of the phase conductor, and the obtained results are compared with the regulatory requirements.